The present invention relates to the use of bacterial species and/or strains that will be indicated later, for preparing a composition for the prevention and/or treatment of hyperoxaluria and of disorders associated with this, as well as the composition thus obtained.
Correspondingly, the said composition can assume the form and perform the activity of a dietary composition or of a food supplement or of a real drug, depending on the supporting or preventive or truly therapeutic action that the composition is intended to exert depending on the particular individuals for whom it is intended. This preventive or truly therapeutic action can derive from colonization, by the said bacteria, of the intestine of subjects at risk of hyperoxaluria or disorders associated with hyperoxaluria.
Hyperoxaluria consists of excessive presence of oxalates in the urine (urinary oxalate  greater than 40 mg/die). As well as being caused by a genetic defect that alters the metabolism of glyoxylic acid with formation of oxalate instead of glycine, it may be a side effect of excessive ingestion of foods rich in oxalate, such as spinach, cocoa, hazelnuts, pepper and tea, or treatment with, for example, anti-obesity drugs (e.g. ORLISTAT). Hence the usefulness of providing a dietary supplement capable of reducing and regulating the presence of oxalates in the urine.
Hyperoxaluria is a predominantrisk factor for the formation of renal calculi and may be caused by excessive absorption of oxalate from the colon or by renal overload caused by hyperoxaluria as in primary hyperoxaluria (PH).
The urinary level of oxalate seems to constitute a crucial sign with regard to the formation of calcium oxalate calculi even in patients with normal urinary excretion of calcium, and calcium oxalate calculi can sometimes also form in patients under strictly oliguric dialysis and without a prior history of nephrolithic disease in that, within this framework, there may be oxalate supersaturation even in a minimal quantity of urine.
The daily excretion of oxalate is related to urinary volume, to the taking of vitamin C, to the body weight index and, inversely, to the intake of calcium.
A study by Sutton and Walker on a population of idiopathic calcium oxalate calculi formers with slight hyperoxaluria was unable to demonstrate any significant alteration of renal control of oxalate, and concluded there was an increased dietary burden of oxalate with a possible hyperabsorption mechanism.
In non-PH hyperoxaluria patients it will therefore be necessary to pay greatest attention to enteral hyperabsorption of oxalate, which promotes the clinical picture of enteric hyperoxaluria and often the recurrent production of renal calculi. It has in fact been recognized since 1968 that nephrolithiasis is a complication of a disease or of resection of the intestine.
Increased intestinal absorption of oxalate, termed enteric hyperoxaluria (EHO), depends on at least two mechanisms. The first is associated with malabsorption of biliary salts in the diseased or resected ileum, which causes a deficiency of biliary salts and malabsorption of fats. Most of the oxalate in the diet is bound to calcium and is scarcely absorbed, but poorly absorbed fats bind intraluminal calcium, lowering the quantity bound to oxalate and giving rise to increased absorption of oxalate. The second mechanism of EHO is associated with increased permeability of the colon for oxalate, caused by poorly absorbed fatty acids and biliary salts, perhaps aggravated by variations of the epithelial occluding junctions of the colon caused by the decrease in intraluminal calcium. This hyperoxaluria is related to the degree of steatorrhoea, and is unusual with ileal resections  less than 30 cm. A decreased count of bacteria that metabolize the colon oxalate (Oxalobacter formigenes) as well as their inhibition by poorly absorbed biliary salts can likewise contribute to EHO. Finally, hyperoxaluria can be observed with long-term parenteral nutrition, also in patients with colectomies and minimal intake by the oral route, perhaps because of increased synthesis of endogenous oxalate.
Oxalate is sparingly soluble in water, but the urine can become supersaturated through the presence of crystallization inhibitors. Hyperoxaluria, combined with a decreased volume of urine and reduced levels of these inhibitors, predisposes to renal calculi.
Parenchymal renal deposition of oxalate can cause interstitial nephritis and nephrocalcinosis, with acute or chronic renal insufficiency.
The treatment of patients with calcium oxalate calculi is complex, and is described below.
Stage 1
Increased intake of liquids for a urinary excretion of 3 l/day;
Diet low in oxalate (avoid spinach, rhubarb, beets, hazelnuts, tea, cola, chocolate, wheat bran, strawberries);
Low-fat diet (50 g/day);
Calcium supplement (1-2 g/day);
Cholestyramine (4 g four times a day);
Stage 2 (if Calculi Recur Despite the Treatment of Stage 1)
Alkalization of the urine and citrate supplement (for example potassium citrate, sodium citrate=30 mEq base four times a day);
Magnesium supplement (to correct the urinary levels);
Allopurinol 300 mg/day (if the calculi contain uric acid).
The possibility of gastroenteric biological manipulation of oxalate had been known since 1955 from documents on the destruction of oxalate by the contents of the cow rumen and, subsequently, by mixed bacterial flora of the large intestine of other herbivores.
Allison referred in 1985 to the specific effect of degradation of oxalate of Oxalobacter formigenes, which inhabits the large intestine of man as well as of other animals.
More recently, Ito demonstrated the degradation of the oxalate content of foods in vitro by means of Eubacterium lentum WIH-1.
Subsequently, the absence of Oxalobacter formigenes was suggested as a risk factor for hyperoxaluria in cystic fibrosis patients.
Enteric hyperoxaluria is therefore the result of excessive enteric absorption of oxalate through increased permeability of the mucosa or increased solubility and bioavailability of faecal oxalate such as when the calcium content of the diet is reduced. The absence of Oxalobacter formigenes can add a new pathophysiological mechanism that is important from the standpoint of therapy.
Now it has been found, surprisingly, that the following bacteria: Streptococcus thermophilus, Lactobacillus brevis, Lactobacillus acidophilus, Lactobacillus plantarum, Bifidobacterium infantis, Bifidobacterium longum and Bifidobacterium breve are capable of growing in the presence of and/or of degrading oxalate.
Accordingly, the present invention provides the use of at least one strain of the following bacteria: Streptococcus thermophilus, Lactobacillus brevis, Lactobacillus acidophilus, Lactobacillus plantarum, Bifidobacterium infantis, Bifidobacterium longum and Bifidobacterium breve for preparing a dietary and/or pharmaceutical composition for the prevention and/or treatment of hyperoxaluria and the disorders associated with this.
Preferably, the strain of Lactobacillus brevis is the strain of Lactobacillus brevis CD2 deposited at the DSMxe2x80x94Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Braunschweig, Germany, on Feb. 6, 1998 with accession number DSM 11988 under the Budapest Treaty, or mutants and derivatives thereof.
More particularly, hyperoxaluria and the disorders associated with it comprise enteric hyperoxaluria, renal calcium oxalate lithiasis, hyperoxalurias from intestinal inflammatory diseases, renal insufficiency, vesical calculosis, cardiopathy from hyperoxaluria, cystic fibrosis and vulvodynia.
Use of the invention includes use in the veterinary field.
According to the invention, the dietary and/or pharmaceutical composition is able to colonize, with the said bacteria, the intestine of subjects at risk of hyperoxaluria or disorders from hyperoxaluria, or disorders from renal calcium oxalate lithiasis.
The invention likewise provides a dietary or pharmaceutical composition comprising at least one strain of the following bacteria: Streptococcus thermophilus, Lactobacillus brevis, Lactobacillus acidophilus, Lactobacillus plantarum, Bifidobacterium infantis, Bifidobacterium longum and Bifidobacterium breve. 
According to one embodiment of the invention, a strain of Streptococcus thermophilus is combined with a strain of Lactobacilius selected from the group consisting of Lactobacillus brevis, Lactobacillus acidophilus and Lactobacillus plantarum or their mixtures. Preferably, the strain of Lactobacillus brevis is the strain of Lactobacillus brevis CD2 deposited at the DSMxe2x80x94Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Braunschweig, Germany, on Feb. 6, 1998 with accession number DSM 11988 under the Budapest Treaty, or mutants and derivatives thereof.
According to another embodiment of the invention, a strain of Streptococcus thermophilus is combined with a strain of Bifidobacterium selected from the group consisting of Bifidobacterium infantis, Bifidobacterium longum and Bifidobacterium breve or their mixtures. In this case, preferably, the proportions between the concentrations of Bifidobacterium infantis, Bifidobacterium longum and Bifidobacterium breve in the mixture, expressed in CFU/g of composition, are preferably 1:1:1.
According to a preferred embodiment, the ratio between the concentrations of Streptococcus thermophilus and of the bacterium of the genus Lactobacillus, expressed in CFU/g of composition, is from 1000:1 to 1:1000, whereas the ratio between the concentrations of Streptococcus thermophilus and of the bacterium of the genus Bifidobacterium or the mixture of bacteria of the genus Bifidobacterium, expressed in CFU/g of composition, is from 1000:1 to 1:1000.
The total concentration of the bacteria is preferably from 106 to 1012 CFU/g of composition.
According to the invention, the composition can moreover contain or be administered in combination with:
substances capable of binding the oxalate in the intestinal lumen, in particular cholestyramine (for example 0.5-4 g/die) and organic hydrocolloids of marine origin,
vitamins, in particular B6 (for example 20-200 mg/die) and C (for example 0.1-2 g/die),
magnesium oxide (for example 50-600 mg/die),
calcium (for example 0.5-2 g/die),
allopurinol (for example 50-300 mg/die),
enzymes, lactic bacteria, hormones and diuretics, immunomodulators, anticancer, lipids, urine alkalizers, urine acidifiers, saturated and unsaturated fatty acids and phospholipids,
drugs bringing about hyperoxaluria as a side effect, for example anti-obesity drugs (e.g. ORLISTAT).
Generally the composition can be administered orally or by the intraluminal route or by enteroclysis in the form of granules, tablets, capsules, suppositories or by enteroclysm.
The invention also provides a food based on chocolate, cocoa, asparagus, tomato, drinks/liquids, spinach, walnuts, hazelnuts, fibres, cereals, potato, tea and peanut butter, containing a quantity of at least one strain of bacteria selected from among Streptococcus thermophilus, Lactobacillus brevis, Lactobacillus acidophilus, Lactobacillus plantarum, Bifidobacterium infantis, Bifidobacterium longum and Bifidobacterium breve, sufficient to colonize the intestine of subjects at risk of hyperoxaluria or disorders arising from hyperoxaluria.
The invention finally provides a method for the prevention and/or treatment of hyperoxaluria and the disorders associated with this by administering, to a subject at risk of hyperoxaluria or a disorder arising from hyperoxaluria, from 0.5 to 4 g/die of the composition of any one of the claims from 4 to 10.
xe2x80x9cSubjectsxe2x80x9d in this context includes humans and animals in general, and in particular farm animals, sport animals and pets.